Conductive pattern and method of making

ABSTRACT

A method of forming an electrically-conductive pattern includes selectively electroplating the top portions of a substrate that corresponds to the pattern, and separating the conductive pattern from the substrate. The electroplating may also include electrically connecting the conductive pattern to an electrical component. Conductive ink, such as ink including carbon particles, may be selectively placed on the conductive substrate to facilitate plating of the desired pattern and/or to facilitate separation of the pattern from the substrate. An example of a conductive pattern is an antenna for a radio-frequency identification (RFID) device such as a label or a tag. One example of an electrical component that may be electrically connected to the antenna, is an RFID strap or chip.

RELATED APPLICATIONS

This application is a continuation-in-part of both U.S patentapplication Ser. No. 10/412,794, filed Apr. 11, 2003, and U.S patentapplication Ser. No. 11/294,039, filed Dec. 5, 2005. This applicationalso claims priority under 35 USC 119 to U.S. Provisional PatentApplication No. 60/845,383, filed Sep. 18, 2006. All of the aboveapplications are hereby incorporated by reference in their entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to methods and devices for producing patternedconductors (conductive patterns), and for producing devices includingconductive patterns.

2. Description of the Related Art

One difficult manufacturing challenge is fabrication of patterns ofelectrically-conductive material, particularly atop dielectricmaterials. One past method of accomplishing the patterning is to etch alayer of conductive material, such as a metal film. However, etching isan exacting process and can be expensive.

An alternative method has been to deposit conductive ink traces on thedielectric material. However, the inks utilized may be expensive, andproblems of continuity of the elements of the conductive pattern mayarise when such a method is used.

One field where conductive patterns are employed is that of radiofrequency identification (RFID) tags and labels (collectively referredto herein as “devices”). RFID devices are widely used to associate anobject with an identification code. RFID devices generally have acombination of antennas (a conductive pattern) and analog and/or digitalelectronics, which may include for example communications electronics,data memory, and control logic. For example, RFID tags are used inconjunction with security-locks in cars, for access control tobuildings, and for tracking inventory and parcels. Some examples of RFIDtags and labels appear in U.S. Pat. Nos. 6,107,920, 6,206,292, and6,262,692, all of which are hereby incorporated by reference in theirentireties.

As noted above, RFID devices are generally categorized as labels ortags. RFID labels are RFID devices that are adhesively or otherwise havea surface attached directly to objects. RFID tags, in contrast, aresecured to objects by other means, for example by use of a plasticfastener, string or other fastening means.

One goal in employment of RFID devices is reduction in the cost of suchdevices.

From the foregoing it will be appreciated that improvements inconductive pattern fabrication methods would be desirable. Inparticular, improvements in RFID devices utilizing conductive patternswould be desirable.

SUMMARY OF THE INVENTION

According to an aspect of the invention, a conductive pattern is formedby plating atop a conductive substrate.

According to another aspect of the invention, a conductive pattern isformed by plating on a patterned conductive ink layer that includes acarbon-containing ink.

According to yet another aspect of the invention, a method of making aconductive pattern includes the steps of: plating the conductive patternatop a conductive substrate; and separating the conductive pattern fromthe conductive substrate.

According to still another aspect of the invention, a method of making aradio frequency identification (RFID) device includes the steps of:plating a conductive pattern atop a conductive substrate, wherein theconductive pattern includes an RFID antenna; coupling the RFID antennato a separation substrate; and separating the separation substrate andthe conductive substrate, thereby separating the RFID antenna from theconductive substrate.

According to a further aspect of the invention, a radio frequencyidentification (RFID) device includes: an RFID chip; an RFID antenna;and electroplated conductive links providing electrical coupling betweenthe chip and the antenna.

According to a still further aspect of the invention, an RFID deviceincludes electroplated links between one or more components, such as achip, an energy storage device, and/or a resonator, and an antenna,and/or between different components. The antenna and the links may beparts of a continuous electroplated conductive pattern.

According to another aspect of the invention, a method of producing anRFID device includes the steps of: depositing a patterned conductive inklayer on a substrate; placing an electrical component in contact withthe conductive ink layer; and electroplating to form a conductivepattern electrically coupled to the electrical component.

According to yet another aspect of the invention, a method of making aconductive pattern includes the steps of: placing a dielectric layer ona conductive substrate, wherein the dielectric layer has openingstherethrough; plating the conductive pattern atop the conductivesubstrate, through the openings; and separating the conductive patternfrom the conductive substrate.

According to a further aspect of the invention, a method of making anRFID device includes the steps of: printing graphics on a front surfaceof a dielectric substrate; forming a conductive pattern on a conductivesubstrate; and after the printing, adhesively transferring theconductive pattern to a back surface of the dielectric substrate.

According to a still further aspect of the invention, an RFID deviceincludes: a dielectric layer; a conductive pattern antenna; a chipoperatively coupled to the antenna; and an adhesive on the dielectriclayer. The adhesive both attaches the antenna to the dielectric layer,and is configured for attaching the RFID device to an object that is notpart of the RFID device.

According to another aspect of the invention, a method of making aconductive pattern includes the steps of: plating the conductive patternatop a conductive substrate that is partly covered with a mask made of alow surface energy material; and separating the conductive pattern fromthe conductive substrate.

According to yet another aspect of the invention, a method of forming anRFID device includes the steps of: forming a first conductive pattern;coupling a chip to the first conductive pattern; positioning adielectric layer over the first conductive pattern; placing a secondconductive pattern on the dielectric layer; and coupling the secondconductive pattern to at least one of the first conductive pattern andthe chip.

According to still another aspect of the invention, a method of makingconductive patterns includes the steps of: plating on a conductivesubstrate to form a plurality of conductive patterns in a continuoussheet of conductive material; separating the continuous conductivematerial sheet from the conductive substrate; and singulating theconductive patterns.

According to a further aspect of the invention, a method of makingconductive patterns includes the steps of: preparing opposite majorsurfaces of a conductive substrate for patterned electroplating; andsimultaneously electroplating conductive patterns onto both majorsurfaces of the conductive substrate.

According to a still further aspect of the invention, a method offorming a conductive pattern includes the steps of: exposing a frontside of a conductive substrate or foil to an electrolyte contained in acell, wherein the conductive substrate or foil is a part of the cell;and electroplating the front side of the conductive substrate or foil,to form the conductive pattern. The conductive substrate or foil may bea web of conductive material that moves along a side of the cell suchthat at any given time a portion of the conductive substrate or foil isin contact with the electrolyte in the cell. The cell may also include:a pair of side walls; an electrode; and seals between the side walls andthe conductive substrate or foil. The portion of the conductivesubstrate or foil may be a bent portion of the conductive substrate orfoil. The bent portion may be a U-shape bent portion. The electroplatingmay include providing a voltage difference across the electrolytebetween the electrode and the conductive foil or substrate; and the cellmay include a power source connected to the electrode and to a back sideof the conductive foil or substrate, to provide the voltage differenceacross the electrode. The power source may be connected to theconductive substrate or foil at a location along the conductivesubstrate or foil that is in contact with the electrolyte. Theelectrolyte may be a liquid electrolyte or a colloidal electrolyte.

According to another aspect of the invention, a method of making an RFIDdevice includes the steps of: forming a conductive pattern on aconductive substrate; adhesively transferring the conductive patternfrom the conductive substrate to a carrier; and adhesively transferringthe conductive pattern from the carrier to an object. The adhesivelytransferring to the carrier may include adhesively transferring using acarrier adhesive that is a switchable adhesive having selectivelyactivatable and deactivatable adhesive properties. The switchableadhesive may include a hot melt adhesive or a temperature switchableadhesive. The adhesively transferring from the carrier may includedeactivating the adhesive properties of the carrier adhesive. Accordingto an aspect, the adhesively transferring to the carrier includesadhesively transferring using a carrier adhesive; the adhesivelytransferring from the carrier includes adhesively transferring using asecond adhesive; and the carrier adhesive and the second adhesive havedifferent adhesive properties. The second adhesive may be an adhesivefilm on a covering layer that is attached to the conductive pattern. Thesecond adhesive may be a patterned adhesive applied to at least parts ofthe conductive pattern. The second adhesive may be atemperature-switchable adhesive. The second adhesive may be a hot-meltadhesive. The second adhesive may be a pressure-sensitive adhesive. Themethod may also include operatively coupling a chip to the conductivepattern, wherein the conductive pattern functions as an antenna whencoupled to the chip. The chip may be part of an interposer that alsoincludes conductive leads attached to contacts of the chip. The chip maybe coupled to the conductive pattern before the adhesively transferring.The chip may be coupled to the conductive pattern after the adhesivelytransferring. The carrier may be a film.

According to yet another aspect of the invention, a method of applyingan RFID device to an object includes the steps of: forming a conductivepattern on a conductive substrate; and adhesively transferring theconductive pattern directly from the conductive substrate to the object.The adhesively transferring includes adhesively adhering the conductivepattern to the object. The method may also include operatively couplinga chip to the conductive pattern, wherein the conductive patternfunctions as an antenna when coupled to the chip. The chip may be partof an interposer that also includes conductive leads attached tocontacts of the chip. The chip may be coupled to the conductive patternbefore the adhesively transferring. The chip may be coupled to theconductive pattern after the adhesively transferring.

According to still another aspect of the invention, a method of makingan RFID device includes the steps of: plating a conductive pattern on aconductive substrate; transferring the conductive pattern from theconductive substrate to a vacuum roller; and transferring the conductivepattern to a device web. The conductive pattern is an antenna for theRFID device. The transferring from the conductive substrate may includeusing a vacuum to secure the conductive pattern to a vacuum pore of thevacuum roller. The transferring to the device web may includetransferring the conductive pattern at a different pitch than on theconductive substrate. The method may include operatively coupling a chipto the conductive pattern, wherein the conductive pattern functions asan antenna when coupled to the chip.

According to a further aspect of the invention, a method of making aconductive pattern includes the steps of: forming a plating mask on aconductive substrate, wherein the forming the mask includes selectivelyoxidizing parts of a surface of the conductive substrate; andelectroplating exposed portions of the surface of the conductivesubstrate, to form the conductive pattern. The forming the mask mayinclude: patterned depositing of a removable mask over portions of theconductive substrate where the conductive pattern is to be formed;oxidizing portions of the conductive substrate not covered by theremovable mask, to thereby produce the plating mask; and removing theremovable mask.

To the accomplishment of the foregoing and related ends, the inventioncomprises the features hereinafter fully described and particularlypointed out in the claims. The following description and the annexeddrawings set forth in detail certain illustrative embodiments of theinvention. These embodiments are indicative, however, of but a few ofthe various ways in which the principles of the invention may beemployed. Other objects, advantages and novel features of the inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the annexed drawings, which are not necessarily to scale:

FIG. 1 is a high-level flowchart of a method in accordance with thepresent invention;

FIG. 2 is an oblique view illustrating the method of FIG. 1;

FIG. 3 is a high-level flowchart illustrating an alterative embodimentmethod in accordance with the present invention;

FIG. 4 is a flowchart illustrating a specific embodiment of the methodsof FIGS. 1 and 3;

FIG. 5 is an oblique view illustrating a first step in the method ofFIG. 4;

FIG. 6 is an oblique view illustrating a second step in the method ofFIG. 4;

FIG. 7 is a cross-sectional view illustrating an example electricalcomponent used in the method of FIG. 4;

FIG. 7A is a plan view illustrating an example of an active RFID deviceformed in accordance with the present invention;

FIG. 7B is a plan view illustrating an example of a semi-passive RFIDdevice formed in accordance with the present invention;

FIG. 8 is an oblique view illustrating a third step of the method ofFIG. 4;

FIG. 9 is a cross-sectional view along line 9-9 of FIG. 8;

FIG. 10 is an oblique view illustrating a fourth step of the method ofFIG. 4;

FIG. 11 is an oblique view illustrating a fifth step of the method ofFIG. 4;

FIG. 12 is a flowchart illustrating another example of the method ofFIGS. 1 and 3;

FIG. 13 is an oblique view illustrating a first step of the method ofFIG. 12;

FIG. 14 is an oblique view illustrating a second step of the method ofFIG. 12;

FIG. 15 is an oblique view illustrating a third step of the method ofFIG. 12;

FIG. 16 is an oblique view illustrating a fourth step of the method ofFIG. 12;

FIG. 17 is an oblique view illustrating a step in an alternateembodiment of the method of FIG. 12;

FIG. 18 is a flowchart illustrating yet another example of the method ofFIGS. 1 and 3;

FIG. 19 is an oblique view illustrating a first step of the method ofFIG. 18;

FIG. 20 is an oblique view illustrating a second step of the method ofFIG. 18;

FIG. 21 is an oblique view illustrating a third step of the method ofFIG. 18;

FIG. 22 is a schematic view illustrating a system for carrying out themethods of FIGS. 1 and 3;

FIG. 23 is a plan view of a first RFID device in accordance with thepresent invention, utilizing a conductive pattern as an antenna;

FIG. 24 is a plan view of a second RFID device in accordance with thepresent invention, utilizing a conductive pattern as an antenna;

FIG. 25 is a plan view of a third RFID device in accordance with thepresent invention, utilizing a conductive pattern as an antenna;

FIGS. 26 and 27 are oblique views illustrating another method inaccordance with the present invention;

FIG. 28 is an oblique view illustrating yet another method in accordancewith the invention;

FIG. 29 is an oblique view illustrating some steps in a method offorming an RFID device in accordance with an embodiment of theinvention;

FIG. 30 is a bottom partial-cutaway view of an RFID device web made bythe method of FIG. 29;

FIG. 31 is a high-level flow chart of steps in a method of forming RFIDdevices in accordance with an embodiment of the invention;

FIG. 32 is a schematic illustration of a system for performing themethod of FIG. 31;

FIG. 33 is a schematic illustration of another variant of the system ofFIG. 32;

FIG. 34 is an oblique view of a patterned conductive substrate forforming a conductive pattern in accordance with an embodiment of thepresent invention;

FIG. 35 is an oblique view illustrating some steps in a method offorming an RFID device in accordance with an embodiment of theinvention;

FIGS. 36-39 are oblique views illustrating some steps of methods offorming multilevel RFID devices in accordance with embodiments of theinvention;

FIG. 40 is an oblique view illustrating some steps in a method offorming a conductive pattern in accordance with an embodiment of theinvention;

FIGS. 41 and 42 are oblique views of conductive substrates for formingcontinuous conductive patterns, according to embodiments of theinvention;

FIGS. 43-45 are schematic illustrations of systems for making continuousconductive patterns, in accordance with embodiments of the presentinvention;

FIGS. 46 and 47 are oblique views of steps of making a conductivepattern in accordance with an embodiment of the present invention; and

FIGS. 48 and 49 are oblique views showing a conductive substrate inaccordance with still another embodiment of the present invention.

DETAILED DESCRIPTION

A method of forming an electrically-conductive pattern includesselectively electroplating the top portions of a conductive substratethat corresponds to the pattern, and separating the conductive patternfrom the conductive substrate. The electroplating may also includeelectrically connecting the conductive pattern to an electricalcomponent. Conductive ink, such as ink including carbon particles, maybe selectively placed on the conductive substrate to facilitate platingof the desired pattern and/or to facilitate separation of the patternfrom the conductive substrate. An example of a conductive pattern is anantenna for a radio-frequency identification (RFID) device such as alabel or a tag. One example of an electrical component that may beelectrically connected to the antenna, is an RFID strap or chip.

In the following description, various methods are described forformation of a conductive pattern, and for formation of conductivepatterns with electrical connection between the patterns to electricalcomponents. Although reference is made throughout to a particularapplication of the disclosed fabrication methods, that of RFID devicessuch as RFID tags or labels, it will be appreciated that the methods maybe utilized for creating a wide variety of conductive patterns andelectrical components.

Referring initially to FIGS. 1 and 2, a method 10 for forming aconductive pattern 12 includes, in step 14, plating the conductivepattern 12 atop a conductive substrate 18. In step 20, the conductivepattern 12 is separated from the conductive substrate 18.

A possible additional step to the method 10 is illustrated with respectto FIGS. 2 and 3, wherein an electrical component 24 is placed atop theconductive substrate 18 in step 26, prior to step 14's plating to formthe conductive pattern 12. Thus, an electrical connection is madebetween the conductive pattern 12 and the electrical component 24. Inthe separation of step 20, the electrical component 24 is separated fromthe conductive substrate 24 along with the conductive pattern 12.

A high-level overview of the fabrication methods of the presentinvention now having been made, details are given regarding severalembodiments of the method 10. Turning now to FIG. 4, several steps areshown for one embodiment of the method 10, a method 40 for forming ormaking a conductive pattern. FIGS. 5-9 illustrate various steps of themethod 40.

In step 42, illustrated in FIG. 5, a patterned conductive ink layer 44is deposited onto the conductive substrate 18. The conductive substrate18 may be any of a wide variety of electrically-conductive materials. Anexample of a suitable conductive material is a metal foil such as analuminum foil. The rate of plating on the aluminum foil may be afunction of the surface roughness of the aluminum. It has been foundelectroplating proceeds at a lower rate on aluminum having a smooth orshiny surface, for example a polished surface, than on aluminum having arough or matte surface, for example surface roughened by sanding.

A wide variety of conductive materials may alternatively be used as thematerial for the conductive substrate 18. Examples of suitablealternative materials include stainless steel and titanium. Otheralternative materials that may be suitable include nickel, silver, gold,certain forms of carbon, and copper, with an appropriate surfacetreatment. Non-metal conductive materials, such as suitableintrinsically conductive polymers may also be utilized in the conductivesubstrate 18.

The conductive ink used in making the patterned conductive ink layer 44may be any of a variety of suitable electrically-conductive inks. Theconductive ink may include carbon particles or metal particles to makeit electrically conductive. One example of an acceptable ink is Acheson440B ink. Alternatively, inks based on black ink for use with regularoffice inkjet printers may be employed. Generally speaking, it isdesirable to have an ink with a high ratio of carbon to polymer binder,so that a high surface area of carbon is achieved. The carbon ink mayhave a thickness of from about 0.5 to about 20 microns, although it willbe appreciated that suitable thicknesses outside that range may be used.

As explained further below, carbon-based ink is desirable in thatplating may occur faster on the carbon-based ink than on uncovered orun-inked parts 45 of the conductive substrate 18. Further, carbon-basedink may have a low adhesion to the conductive substrate 18, allowing foreasy removal of the carbon-based ink and the overlying plated conductivepattern. It will be appreciated that the preferential plating ofmaterial on the carbon-based ink, as opposed to on the un-inked parts45, may occur only for certain combinations of ink, conductive substrate(material and/or surface properties), and/or plating material.

It will be appreciated that additives may be included in the ink to makethe ink easily detachable from the conductive substrate 18. For example,the ink may include wax or other substances having a relatively lowmelting temperature. Heating of the ink may facilitate removal of theconductive pattern plated on top of the conductive ink layer 44. As anexample, the conductive ink may have approximately two parts by weightgraphite per part polymer binder or wax. Other additives that may beincluded in the ink may include polymers with low glass transitiontemperatures T_(g), (the temperature at which plastic material willchange from the glassy state to the rubbery state). Also, ink withreduced carbon content may be used to facilitate separation of theconductive pattern 12 from the conductive substrate 18. More broadly,the carbon content of the ink may be reduced or increased, depending onthe binder, to facilitate separation.

Of course, a wide variety of other suitable conductive materials may beincluded in the ink, for example an intrinsically conductive polymersuch as polyethylenedioxythiophene (PEDOT), polypyrrole (PPy), orpolyaniline (PANI); silver particles; copper particles; nickelparticles; or conductive metal oxide particles. More broadly, a widerange of conductive metal powders or conductive metal compound powdersmay be utilized as additives. It will be appreciated that a high surfacearea for the conductive particles would be desirable. Generally,however, it will be expected that carbon-based inks may be lessexpensive than metal-based conductive inks.

It will be appreciated that a variety of suitable non-ink depositableconductive materials may be used as alternatives to or in addition toconductive inks.

A variety of printing methods may be utilized in depositing thepatterned conductive ink layer 44, such as screen printing, flexoprinting, gravure printing, or inkjet printing.

In step 46, illustrated in FIG. 6, the electrical component 24 is placedatop the conductive substrate 18, for subsequent electrical connectionto the conductive pattern 12. The electrical component 24 may be placedatop parts of the patterned conductive ink layer 44 before theconductive ink layer 44 has dried. Subsequent drying of the conductiveink layer 44 may then serve to adhere the electrical component 24 to theconductive ink layer 44. The adherence between the electrical component24 and the conductive ink layer 44 may not be a strong, permanentattachment, but may only be sufficient to provide securement duringsubsequent plating processes.

As an alternative method of securing the electrical component 24 to theconductive ink layer 44 and/or the conductive substrate 18, theelectrical component 24 may have an adhesive thereupon, such as aconductive or non-conductive pressure-sensitive adhesive. Pressing theadhesive against the patterned conductive ink layer 44 and/or theconductive substrate 18 secures the electrical component 24 in place. Itwill be appreciated that many alternative suitable adhesives may beused, for example heat-activated adhesives. It will further beappreciated that alternatively, the adhesive may be placed on thepatterned conductive ink layer 44 and/or the conductive substrate 18,with the electrical component 24 then placed upon the adhesive. Theadhesive may be deposited by any of a variety of suitable, well-knownmethods.

The electrical component 24 may be any of a variety of electricalcomponents to be coupled to, and to perhaps interact with, theconductive pattern 12 to be formed. In one embodiment the conductivepattern 12 may be an antenna and the electrical component 24 may be aradio-frequency identification (RFID) chip or strap to be electricallycoupled to the antenna. Examples include an RFID strap available fromAlien Technologies, and the strap marketed under the name I-CONNECT,available from Philips Electronics. As shown in FIG. 7, an RFID strap 50may include an RFID chip 52 (an electronic device for sending andreceiving RF signals), conductive leads 54 for making electricalconnections to the chip, and an insulating substrate 56 for supportingthe conductive leads 54 and the chip 52.

More broadly, the electrical component 24 (FIG. 6) may be any of avariety of RFID devices, including active, passive, or semi-passive RFIDdevices. An active RFID device is defined as an RFID device thatincludes its own power source and generates an RF signal. A passive RFIDdevice is defined as an RFID device that does not include its own powersource, and which responds to a signal by modulated reflection of thesignal. A semi-passive RFID device is defined as an RFID device thatincludes its own power source, for providing at least part of its power,but which responds to a signal by modulated reflection of the signal.

An example of an active RFID device 57 is illustrated in FIG. 7A. Theactive RFID device 57 includes an RFID chip 58, a SAW resonator 59, anda battery 60. The conductive pattern 12 attached to the components ofthe active RFID device 57 may include an antenna, such as a simple loopantenna. The conductive pattern 12 may also include traces for suitablyconnecting the components 58-60 together.

Turning now to FIG. 7B, an example of a semi-passive RFID device 61includes an RFID chip 62 and a battery 63 operatively coupled to theconductive pattern 12. As with the active RFID device 57 shown in FIG.7A and described above, the conductive pattern 12 may include tracesoperatively coupling the components of the semi-passive device 61, inaddition to including an antenna such as a loop antenna or an antennawith another configuration.

The batteries 60 and 63 may be traditional batteries, for exampleflexible thin-film batteries sold by Cymbet Corporation of Elk Ridge,Minn., USA, which are described further in International Publication WO01/73864, which is hereby incorporated by reference in its entirety.Alternatively, the batteries 60 and 63 may be other sorts of devices forproviding stored energy, such as printed super capacitors.

The batteries 60 and 63 may be configured so as to be de-activated untilafter the conductive pattern 12 is fabricated, thus avoiding shortingduring fabrication processes, such as during the plating operationdescribed below. Suitable methods of de-activation depend on the batterytype. For zinc-air batteries a part of the finished RFID label or otherstructure may be removable, and when removed, such as by being torn off,may open an aperture and activate the battery. For lithium batteries,there may be a wax passivation inside the battery over the activematerials, which is melted and removed when heat is applied.

In step 64 of the method 40, illustrated in FIG. 8, a conductivematerial is plated onto the patterned conductive ink layer 44 (FIG. 6)and the conductive substrate 18. The plating is done by a conventionalelectroplating operation using the conductive substrate 18 and theconductive ink layer 44 as one electrode of a system for forming aplating layer 66 by removing conductive material ions from a solution.The plating layer 66 may be any of a variety of suitable, platable,conductive materials. One example of such a suitable material is copper.Alternatively, an intrinsically conductive polymer may be used in placeof copper plating. Examples of suitable intrinsically conductivepolymers include PEDOT, PPy, and PANI. Plating a conductive polymermaterial may be done by an oxidative process, and may involve use of anoxidation-resistant conductive substrate.

The plating layer 66 includes a conductive pattern material portion 68over the patterned conductive ink layer 44 (FIG. 6). In addition, dotsor patches of an additional plated material portion 69 may form over theparts of the conductive substrate 18 not covered by the patternedconductive ink layer 44 (the un-inked parts 45 (FIG. 6) of theconductive substrate 18). In other words, plating may preferentiallyoccur upon the patterned conductive ink layer 44. The preferentialplating on the patterned conductive ink layer 44 results in a continuousplating layer only in the conductive pattern material portion 68. Theadditional plated material portion 69 may be substantiallydiscontinuous, for example, being isolated dots or patches and/or beingof insignificant thickness. The lack of continuous plated material inthe un-inked parts 45 may advantageously reduce undesired electricalconnections between parts of the conductive pattern material portion 68,thus possibly reducing the potential for electrically-induced damage tothe electrical component 24. For carbon-based inks, copper maypreferentially bond to the carbon in the ink at a faster rate than tothe un-inked parts 45 of conductive substrate 18, such as un-inkedportions of a smooth aluminum surface. Electroplated copper forms amatrix with carbon in the carbon-based inks, attaching the carbon andperhaps other components of the ink, to the copper that is formed by theplating. The carbon thus may act as a catalyst for plating of copper.

The thickness of the conductive pattern material portion 68 may be anyof a wide variety of suitable thicknesses, depending on the applicationfor the conductive pattern 12 (FIG. 2). For RFID antennas, thickness maybe on the order of 18-30 microns for antennas used with 13.56 MHzsystems, may be about 3 microns for antennas used with 900 MHz systems,and may be less than 3 microns for antennas used with 2.45 GHz systems.However, these thicknesses are merely examples, and it will beappreciated that conductive patterns 12 with a wide variety of otherthicknesses may be employed.

It will be appreciated that electroplating does not occur on surfacesnot covered by a conductive material. There may be a gap 70 in theplating layer 66 over all or part of the electrical component 24. Thismay be due to part of the electrical component 24 being made of adielectric material, such as a non-conductive plastic housing. It willbe appreciated that parts of the electrical component 24 may be coveredwith a dielectric material prior to or after placement on the conductivesubstrate 18 and/or the patterned conductive ink layers 44 (FIG. 6), toprevent plating thereupon.

By plating atop the conductive substrate 18, it will be appreciated thathigher current densities may be employed, when compared to typicalplating processes using conductive traces atop a dielectric substrate.In addition, the plating described herein may advantageously producemore uniform conductive patterns when compared to plating along thinconductive lines on dielectric substrates.

The conductive pattern material portion 68 of the plating layer 66 atopthe patterned conductive ink layer 44 (FIG. 6) is a conductive pattern12 having a pattern corresponding to that of the patterned conductiveink layer 44. Thus, the plating in step 64 results in formation of theconductive pattern 12, and the conductive pattern material portion 68referred to hereafter as the conductive pattern 12.

As illustrated in FIG. 9, the plating in step 64 may serve to formconductive links 74 coupling the conductive pattern 12 to conductiveleads of the electrical component 24, such as the conductive leads 54 ofthe RFID strap 50. In addition, the links may help physically secure theelectrical component 24 to the conductive pattern 12.

In step 80, illustrated in FIG. 10, an adhesive layer 84 is depositedonto the plating layer 66. The adhesive layer 84 covers at least some ofthe conductive pattern 12, and may cover all of the conductive pattern12. The adhesive layer 84 may optionally cover all of the plating layer66. The adhesive layer 84 is used in separating the conductive pattern12 from the conductive substrate 18. The adhesive layer 84 may be any ofa variety of suitable adhesives, such as pressure-sensitive adhesive orother types of adhesives described above. The adhesive layer 84 mayinclude a thermoset adhesive, an adhesive that is activated by heat.

The adhesive layer 84 may be deposited by printing or by other suitablemeans, such as depositing by use of a roller.

In step 90, a dielectric substrate or sheet 92 (FIG. 11) is laminatedatop the conductive substrate 18, onto the adhesive layer 84. Thedielectric substrate or sheet is also referred to herein as a separationsubstrate or layer. The dielectric substrate or sheet 92 is thusadhesively bonded, via the adhesive layer 84 to the conductive pattern12. In step 94, the dielectric substrate 92, with the attachedconductive pattern 12, is separated from the conductive substrate 18. Instep 96, the conductive pattern 12 and the electrical component 24 maybe processed further. For example, the conductive pattern 12 and theelectrical component 24 may be transferred to an object other than thedielectric substrate 92. Alternatively, other components or layers maybe formed onto or in conjunction with the conductive pattern 12, theelectrical component 24, and/or the dielectric substrate 92. Forexample, a printable layer or a release sheet may be added to produce anRFID device such as a RFID tag or a RFID label.

A wide variety of processes may be utilized in the separation of theconductive pattern and the electrical component 24 from the conductivesubstrate 18. As one example, the dielectric substrate 92 may be aflexible material such as paper or polyester, and the adhesive layer 84may be a pressure-sensitive adhesive. The dielectric substrate 92 may bepressed onto the adhesive layer 84 to join the dielectric substrate 92to the conductive pattern 12. When the dielectric substrate 92 is peeledaway from the conductive substrate 18, the conductive pattern 12 mayhave greater adherence to the dielectric substrate 92 than to theconductive substrate 18, causing the conductive pattern 12 and theelectrical component 24 to peel away from the conductive substrate 18 aswell. Alternatively, the dielectric substrate 92 may be a rigidmaterial, with, for example, a flexible conductive substrate 18 peeledaway from the dielectric substrate 92.

Although reference has been made to the substrate 92 as a dielectricsubstrate, it will be appreciated that all or parts of the substrate 92may be partially or wholly an electrically conducting material. If partof the substrate 92 is electrically conducting, the substrate 92 mayhave a surface layer of a dielectric material, for example, to contactthe conductive pattern 12 without undesirably electrically connectingvarious parts of the conductive pattern 12. Thus, the dielectricsubstrate 92 may be more broadly considered as a separation substrate,that is, as a substrate used in separating the conductive pattern 12from the conductive substrate 18.

It will be appreciated that separation is facilitated by having theconductive pattern 12 be more adherent to the separation substrate 92than to the conductive substrate 18, during the separation process.Thus, the adhesive layer 84 may have greater adherence to the conductivepattern 12 than the conductive pattern 12 has to the conductivesubstrate 18. As noted, the separation process may be preceded by or mayinclude changing of the adherence of the conductive ink layer 44 and/orthe adhesive layer 84. Such changes may be accomplished by processessuitable to the adhesives, such as heating or pressure.

The separation substrate 92 and the conductive substrate 18 may beotherwise pulled from one another. In addition, the conductive pattern12 may be removed from the conductive substrate 18 by use of otherforces, for example, by use of a suitable magnetic force. As anotheralternative, high frequency ultrasonic forces may be used forseparation. The ink layer 44, between two hard materials, the conductivepattern 12 and the conductive substrate 18, may be weakened byresonating the conductive substrate 18, for example, making theconductive pattern 12 more peelable from the conductive substrate 18.

Further variations on the above method are possible. For example, theadhesive layer 84, rather than being placed or deposited on the platinglayer 66, may instead be printed or otherwise suitably deposited uponthe dielectric layer 92. In addition, as suggested above, separation ofthe conductive pattern 12 from the conductive substrate 18 may involveadditional steps, such as activating the adhesive layer 84 by heating orother suitable methods, and/or de-activation or weakening of an adhesivebond between the conductive ink layer 44 and the conductive substrate 18and/or between the conductive ink layer 44 and the conductive pattern12.

The conductive pattern 12 may include part or substantially all of theconductive ink layer 44. That is, the conductive ink of the conductiveink layer 44 may become embedded in or otherwise attached to the platedmaterial of the conductive pattern 12. Alternatively, or in addition,all or part of the conductive ink layer 44 may form a residue whichadheres to either or both the conductive substrate 18 and/or the platedmaterial of the conductive pattern 12. It will be appreciated that sucha residue may be removed, if desired, by a variety of suitable methods,including suitable washing and/or wiping processes, either of which mayinvolve use of suitable solvents.

It will be appreciated that the electrical component 24 may be omittedentirely. Thus the conductive pattern 12 may be produced as a separateitem. Such a separate conductive pattern 12 may be joined to theelectrical component 24 in a later step, through use of suitablewell-known processes. For example, soldering or conductive adhesives maybe used to electrically connect the conductive pattern 12 to theelectrical component 24 or other electrical components.

An alternative to soldering the electrical component 24 to theconductive pattern 12 is welding. Welding is advantageously accomplishedwhile the conductive pattern 12 is adhered to the conductive substrate18, in that the weld current will tend to flow vertically down throughthe conductive pattern 12 and into the conductive substrate 18. Anyinduced voltage may thus be shorted by the conductive substrate 18,reducing or eliminating the potential for electrical-induced damage tothe electrical component 24.

The soldering, welding, or connection with a conductive adhesive,between the conductive pattern 12 and the electrical component 24, mayoccur before removal of the conductive pattern 12 from the conductivesubstrate, or alternatively, after the removal. However, it will beappreciated that the conductive pattern 12 may be a separate articlerequiring no connection to an electrical component. For example, theconductive pattern 12 may be used separately as a decorative or othervisually-distinctive item, wholly apart from the conductive nature ofthe material. It will be appreciated that the conductive pattern 12 maybe used at the same time for both electrical and non-electricalproperties.

It will be appreciated that a wide variety of electrically-conductivepatterns may be formed using the method 40 described above. As notedalready, two possible uses for such conductive patterns are asdecorative elements and as antennas for RFID devices. Another possibleapplication for the method is in production of circuit cables or printedcircuit boards, such as those used to couple together electronicdevices. Such cables often require fine-resolution, flexible arrays ofconductive elements, mounted on a plastic or other flexible substrate.In making such arrays, the dielectric or separation substrate 92 may bea flexible plastic such as polyester, polyimide, polyethyleneterephthalate (PET), polypropylene or other polyolefins, polycarbonate,or polysulfone.

FIG. 12 is a flowchart illustrating a method 100, an alternativeembodiment of the method 10, that involves placing a patterneddielectric layer on the conductive substrate. In step 102, illustratedin FIG. 13, a patterned dielectric mask 108 is placed on the conductivesubstrate 18. The dielectric mask has one or more openings 110corresponding to desired locations for forming portions of theconductive pattern 12. The dielectric mask 108 covers portions of theconductive substrate 18, to prevent plating of the covered portions.

The dielectric mask 108 may be any of a variety of suitable materials.According to one embodiment of the invention a dielectric material maybe printed in the desired pattern on the conductive substrate 18. Avariety of suitable printing methods may be used to print the dielectricmask 108. One example of a suitable dielectric material is a UV-curablematerial, catalog number ML-25198, available from Acheson Colloids, ofPort Huron, Mich., U.S.A.

Alternatively, the dielectric mask 108 may be a pre-formed solid maskthat is placed upon the conductive substrate 18. The pre-formeddielectric mask may be a rubber or polymer mask having the openings 110formed therein. In addition, inorganic materials, such aselectrically-insulating enamel, may be used in the dielectric mask 108.An adhesive layer or other layer may be used to seal the underside ofthe dielectric mask 108 to prevent seepage of electrolyte and resultantplating.

It will be appreciated that other suitable, well-known methods may beused for forming a suitable dielectric mask 108.

In step 112, a patterned conductive ink layer 114, shown in FIG. 14, isdeposited into the openings 110 of the dielectric mask 108. Theconductive ink may be similar to the types of conductive ink discussedabove with regard to the patterned conductive ink layer 44 (FIG. 5). Theconductive ink layer 114 may be deposited by printing or by othersuitable methods, such as blade coating.

In step 118, electroplating is used to form the conductive pattern 12,as illustrated in FIG. 15. The plating process may be similar to thatdescribed above with regard to step 64 of the method 40. The exposedsurfaces of the dielectric mask 108 will generally not be plated duringthe plating process, as the plating is confined to exposed portionswhich conduct electricity from the conductive substrate 18.

As illustrated in FIG. 16, an adhesive layer 120 is then deposited ontothe conductive pattern 12, in step 124. The materials and method ofdeposit for the adhesive layer 120 may be similar to those for theadhesive layer 84 (FIG. 10). The adhesive layer 120 may be depositedsuch that it leaves portions 126 of the dielectric mask 108substantially free of adhesive.

Following placement of the adhesive layer 120 a separation or dielectricsheet is laminated onto the adhesive layer in step 130, and theconductive pattern 12 is separated from the conductive substrate 18 instep 140. Details of these steps may be similar to those of thecorresponding steps of the method 40 (FIG. 4). The dielectric mask 108may be attached to the conductive substrate 18 such that it remainsattached to the conductive substrate 18 even as the conductive pattern12 is peeled off or otherwise separated from the conductive substrate18. This may be due to strong adherence between the dielectric mask 108and the conductive substrate 18. Alternatively, the separation of theconductive pattern 12, and not the dielectric substrate 108, may be dueto a relatively weak adhesion between the dielectric mask 108 and theseparation or dielectric substrate. An adhesive may be utilized inattaching the dielectric mask 108 to the conductive substrate 18.

The method 100 described above may be modified by placing the electricalcomponent 24 in a suitable location on the conductive ink 114 prior toplating, as is illustrated in FIG. 17. The electrical element 24 may beplaced before the conductive ink 114 is dried, thereby adhering it tothe conductive ink 114 on drying. Alternatively, a suitable adhesive maybe used to adhere the electrical element 24 to the conductive ink 114.It will be appreciated that other steps of the method 100 may be carriedout in a similar manner to that described above.

As another alternative, the conductive ink 114 may be omitted entirely,with the plating involving plating material directly on the conductivesubstrate 18 through the openings 110. Materials for the plating and forthe conductive substrate 18, as well as other materials involved, may beselected such that the material directly plated on the conductivesubstrate 18 is able to be separated from the conductive substrate 18,thereby forming a separate conductive pattern.

It will be appreciated that some of the steps in the methods 40 and 100may be varied or performed in an order different from that describedabove. For example, in the method 100, the conductive ink may be placedprior to the placement of the patterned dielectric layer. For example,the conductive ink may be a uniform layer on the conductive substrate 18with the dielectric mask 108 relied upon to prevent plating except wheredesired for formation of the conductive pattern 12. Alternatively, theplacement of the conductive ink on the conductive substrate 18 may be apatterned placement, with the dielectric mask 108 then formed to, forexample, “fine tune” resolution of the conductive pattern 12. Also, byplacing the dielectric mask 108 over areas of the conductive substrate18 that do not correspond to the conductive pattern 12, plating isconcentrated toward areas where the conductive pattern 12 is to beformed, thus reducing material consumption and cost.

Although the dielectric mask 108 has been described above as beingadhered to the conductive substrate 18 during the separation of theconductive pattern 12 from the conductive substrate 18, it will beappreciated that other alternatives may be possible. For example, thedielectric mask 108 may be separated from the conductive substrate 18 atthe same time that the conductive pattern 12 is separated from theconductive substrate 18. The dielectric mask 108 may then be separatedfrom the conductive pattern 12, or alternatively, left to remainconnected to the conductive pattern 12. As another alternative, thedielectric mask 108 may be separately removed, for example, with asolvent, after the electroplating and prior to or after separation ofthe conductive pattern 12 from the conductive substrate 18.

FIG. 18 is a flow chart of another alternate method, a method 150 forfabricating the conductive pattern 12 in connection with the electricalcomponent 24. In step 152, illustrated in FIG. 19, the electricalcomponent 24 is placed on the conductive substrate 18. The electricalcomponent is placed in a “face-up” configuration, such that theconnection points for linking the conductive pattern 12 to theelectrical component 24 are exposed. For example, if the electricalcomponent 24 is an RFID strap 50 (FIG. 7), the strap 50 may be placedwith its conductive leads 54 uncovered and facing upward.

The electrical component 24 may be secured to the conductive substrateby use of a suitable adhesive, or by other suitable means. Also, theelectrical component 24 may be placed in a depression in the conductivesubstrate 18 by fluidic self assembly methods. Further descriptionregarding such methods may be found in U.S. Pat. Nos. 5,783,856,5,824,186, 5,904,545, 5,545,291, 6,274,508, 6,281,038, 6,291,896,6,316278, 6,380,729, and 6,417,025, all of which are hereby incorporatedby reference in their entireties.

In step 154, illustrated in FIG. 20, the patterned conductive ink layer44 is printed or otherwise deposited. Parts of the conductive ink layer44 may cover parts of the electrical component 24, thereby assuring goodcontact between the electrical component 24 and the subsequently-formedconductive pattern 12. For example, parts of the conductive ink layer 44may cover parts of the conductive leads 54 that are parts of the RFIDdevice 50 that may be utilized as the electrical component 24.

In step 156, illustrated in FIG. 21, electroplating is performed to formthe plating layer 66. The conductive pattern material portion 68 overthe patterned conductive ink layer 44 includes conductive links 74providing electrical connection between the electrical component 24 andthe conductive pattern 12. In addition, the conductive links 74 mayinclude portions plated directly on contacts of the electrical component24, such as directly on parts of the conductive leads 54 of the RFIDdevice 50. The continuity of plated material from the conductive pattern12, through the conductive links 74, to parts of the electricalcomponent 24, provides strong electrical and mechanical coupling betweenthe conductive pattern 12 and the electrical component 12.

Finally in step 160 the conductive pattern 12 and the electricalcomponent 24 are separated from the conductive substrate 18. Theseparation process may be similar to separation processes discussed indetail with regard to other methods discussed above.

It will be appreciated that the method 150 may be suitably modified toemploy a dielectric layer such as the dielectric layer 108 (FIG. 13)utilized in the method 100 (FIG. 12).

The methods described above may be performed in one or more roll-to-rolloperations wherein a system 200 for performing such an operation isschematically illustrated in FIG. 22. The below description is only anoverview, and further details regarding roll-to-roll fabricationprocesses may be found in U.S. Pat. No. 6,451,154, which is herebyincorporated by reference in its entirety.

The conductive substrate material 18 moves from a conductive substratesupply roll 202 to a conductive substrate take-up roll 204. A conductiveink printer 208 is used to print the patterned conductive ink layer 44on the conductive substrate 18. The electrical component 24 is thenplaced in contact with the conductive ink layer 44 at a placementstation 212. As shown in FIG. 22, the electrical components 24 arelocated on a web 216 of material, for example, being lightly adhesivelycoupled to the web 216. The web proceeds from a web supply roll 218 to aweb take-up roll 220. A pair of press rollers 224 and 226 press the web216 down toward the conductive substrate 18, bringing the electricalcomponent 24 into contact with the patterned conductive ink layer 44. Asdescribed above with regard to the method 40, the electrical component24 may be adhesively coupled to the conductive ink layer 44, andseparated from the web 216.

It will be appreciated that the placement station 212 may alternativelyhave other sorts of devices for placing the electrical components 24onto the patterned conductive ink layer 44. For example, the placementstation 212 may include one or more pick-and-place devices and/or rotaryplacers. Examples of pick-and-place devices include the devicesdisclosed in U.S. Pat. Nos. 6,145,901, and 5,564,888, both of which areincorporated herein by reference, as well as the prior art devices thatare discussed in those patents. An example of a rotary placer isdisclosed in U.S. Pat. No. 5,153,983, the disclosure of which isincorporated herein by reference.

After placement of the electrical components 24, the conductive inklayer may be suitably dried at a drying station 228, for example bysuitably heating the conductive substrate 18 and its surroundings.

The conductive substrate 18 thereafter moves into and through a platingbath 230, in which the electroplating occurs. It will be appreciatedthat the plating bath 230 may be configured so that each part of theconductive substrate 18 has a sufficient residence time so as to form aplating layer 66 of the desired thickness. The conductive substrate 18is guided through the plating bath 230 by rollers 232, 234, and 236.

An adhesive printer 240 is then used to print the adhesive layer 84 atopthe plating layer 66. The adhesive layer 84 may be dried at a dryingstation 242.

Finally, separation of the conductive pattern 12 from the conductivesubstrate 18 is accomplished at a separation station 250. A separationsubstrate 92 moves from a separation substrate supply roll 252 to aseparation substrate take-up roll 254. A pair of press rollers 256 and258 press the separation substrate onto the adhesive layers 84, therebyadding the separation substrate 92 to the laminate based on theconductive substrate 18. The separation substrate 92 is pulled away fromthe conductive substrate 18 and towards the separation substrate take-uproll 254. As discussed above, the conductive pattern 12 and theelectrical component 24 preferentially adhere to the separationsubstrate 92, and are pulled off the conductive substrate 18.

It will be appreciated that other operations may be performed, such ascleaning of the conductive substrate 18, which may then be re-used.

As alternatives to the roll-to-roll operation shown and described, theconductive substrate 18 may be part of a continuous loop of material, ora rotating drum of material, enabling the conductive substrate 18 to becontinuously re-used.

The roll-to-roll operation illustrated in FIG. 22 and described above isbut one example of a range of suitable operations. Alternatively, themethod 10 may involve multiple roll-to-roll operations, as well asoperations that are not performed in a roll-to-roll manner.

FIG. 23 illustrates one possible configuration for the conductivepattern 12, an antenna 300 coupled to an RFID strap 50 to produce anRFID device 302. FIG. 24 shows another possible antenna configuration,an antenna 310 that is part of an RFID device 312. FIG. 25 shows yetanother possible antenna configuration, an antenna 320 that is part ofan RFID device 322.

It will be appreciated that the antennas shown in FIGS. 23-25 mayalternatively be coupled to suitable electronics for forming other typesof RFID devices, such as active or semi-passive RFID devices. Examplesof such devices are shown in FIGS. 7A and 7B, and are discussed above.

FIGS. 26 and 27 illustrate another embodiment, utilizing anon-conductive substrate. Referring to FIG. 26, the conductive ink layer44 may be deposited on a non-conductive substrate 400. An electricalcomponent 24 may be placed on and in contact with the conductive inklayer 44. The non-conductive substrate 400 may include plastic oranother suitable material.

The conductive ink layer 44 may include portions electrically couplingtogether various of the portions where plating is desired, to therebyfacilitate plating. It will be appreciated that different parts of theconductive ink layer 44 may include different types of ink. For example,portions of the layer 44 where plating is desired may include an inkthat preferentially encourages plating, when compared with other areasof the conductive ink layer 44 where plating is not desired.Alternatively, portions of the conductive pattern 12 to be formed mayhave a lower adherence to the non-conductive substrate 400 than theadherence of other portions of the conductive ink layer 44.

Turning now to FIG. 27, electroplating may be used to form theconductive pattern 12 atop the non-conductive substrate 400, includingforming conductive links with the electrical component 24. Following theelectroplating, the conductive pattern 12 and the electrical component24 may be separated from the non-conductive substrate, for example usingan adhesive to peel the conductive pattern 12 and electrical component24 from the non-conductive substrate 400.

FIG. 28 illustrates yet another embodiment of the invention, where adielectric layer or mask 108 covers parts of a conductive substrate 18.The mask also has openings 110 therein, leaving parts 502 of theconductive substrate 18 uncovered. Electroplating is then performed toform a conductive pattern 12, such as that shown in FIG. 2, on theun-inked, uncovered parts 502 of the conductive substrate 18. Theconductive pattern 12 may then be separated from the conductivesubstrate 18.

The conductive substrate 18 may have a roughened surface at least on theparts 502 upon which the conductive pattern 12 is formed. The surfaceroughness may provide faster plating of the conductive pattern 12. Anexample of a suitable roughening method for aluminum is rubbing thealuminum surface with 320 grit sandpaper.

A thin layer of a suitable material, such as oil, may be placed on theotherwise-uncovered parts 502, prior to the plating of the conductivepattern 12, to facilitate subsequent separation of the conductivepattern 12 from the conductive substrate 18.

As an alternative to the method described with regard to FIG. 28, it maybe possible to dispense with the need for the dielectric layer or mask108, by selectively roughening the parts 502 of the conductive substrate18 upon which formation of the conductive pattern 12 is desired. Asalready mentioned above, electroplating may preferentially occur on theroughened surface. That is, electroplated material may be deposited at afaster rate on a rough or roughened surface, as compared with a smoothsurface. The difference between rougher and smoother surface in growthrates and/or adherence may be sufficient to allow suitable selectiveplating and separation of the conductive pattern 12, without use of themask 108.

FIGS. 29 and 30 show part of the process of formation of a web material600 of devices 604, such as RFID devices, that include conductivepatterns 12. The web 600 (which may be part of a roll) includes aprintable substrate 612 that is printed by a printer 614 with graphics616 on a front surface 617. The printable substrate 612 may be made of asuitable printable dielectric material such as paper or one or more ofthe polymer materials described above with regard to the substrate 92(FIG. 11). The graphics 616 may be any sort of suitable printed matter,including words, symbols, and/or pictures. The printer 614 may utilizeany of a variety of suitable printing techniques.

As described earlier, the conductive patterns 12 may be formed on aconductive substrate or foil 18. A printable substrate 612 is coatedwith an adhesive layer 618 on a back surface 619. The adhesive layer 618is used for removing the conductive patterns 12 from the conductivesubstrate or foil 18. This removal step may be similar to that describedabove with regard to the dielectric substrate or sheet 92 and theadhesive 84 (FIG. 11). The adhesive layer 618 may be suitably coated orsprayed onto the printable substrate 612 by a coating or sprayingdevice. As described above, the adhesive layer 618 and the graphics maybe on opposite sides (opposite major surfaces) of the printablesubstrate 612.

It will be appreciated that the conductive patterns 12 may each have arespective interposer (strap) or chip 622 coupled thereto. Theconductive patterns 12 may thus function as antennas for individual RFIDdevices that include the interposers or chips 622.

After the conductive patterns 12 are adhered to the printable substrate612, the adhesive layer 618 may be covered by a release layer 626. Therelease layer 626 may facilitate rolling up of the material 600 withoutunwanted adherence of various layers to one another. The release layer626 may also protect the underlying adhesive layer 618 from dirt orother contaminants.

The finished roll material 600 subsequently may have its individual RFIDlabels (or other devices) 604 singulated and adhered to objects. Theadhesive layer 618 may be used to adhere the individual RFID labels 604to the objects. Thus the adhesive 618 may serve a dual purpose, beingused both for adhering the conductive patterns 12 to the printablesubstrate 612, and for adhering the RFID labels 604 to objects.

The use of the printable (and printed) substrate 612 for removing theconductive patterns 12 from the conductive substrate or foil 18 mayreduce the cost, thickness, and/or complexity of the RFID or otherdevices 604, for instance by eliminating the need for a separatesubstrate layer.

It will be appreciated that the devices 604 may include additionallayers not shown, such as a protective covering layer. Also, it will beappreciated that additional steps may be performed in the fabrication ofthe roll 600 of the devices 604.

FIG. 31 shows the steps of a method 650 for fabricating an RFID device,and FIG. 32 schematically illustrates a system 654 for carrying out oneembodiment of the method 650. In step 656 of the method 650, a series ofconductive patterns 12 is formed on a conductive substrate foil 18. Theconductive substrate foil 18 may be a steel foil or any of the othersuitable foil materials described above. The formation of the conductivepatterns 12 may be in accordance with any suitable of the methodsdescribed herein.

In step 658 the conductive patterns 12 are transferred to a carrier 660.The carrier 660 is shown as a film, but it will be appreciated that thecarrier may alternatively be other sorts of structures, such as a foil,a sheet (such as a paper sheet), or a drum or cylinder. The carrier 660is covered with a carrier adhesive layer 664. The carrier adhesive layer664 is used to pull the conductive patterns 12 off of the conductivesubstrate foil 18, in a manner similar to that of the adhesive layer 84on the substrate or sheet 92 (FIG. 11). The carrier 660 may be asuitable polymer film, such as a PET film. The carrier adhesive 664 maybe an adhesive that is a switchable adhesive, defined herein as anadhesive with adhesive properties that may be selectively activated anddeactivated. Examples of such switchable adhesives include suitable hotmelt adhesives and temperature switchable adhesives. The adhesiveness ofthe carrier adhesive layer 664 may be activated to cause the conductivepatterns 12 to be easily transferred to the carrier 660. As explainedbelow, in a subsequent step the adhesiveness of the carrier adhesivefilm layer 664 may be deactivated to facilitate removal of theconductive patters 12 from the carrier 660.

In step 668 RFID chips or interposers 670 are operatively coupled to theconductive patterns 12. The chips or interposers 670 are attached to theconductive patterns 12. The chips or interposers 670 are alsoelectrically coupled to the conductive patterns 12, either by directohmic coupling or by indirect capacitive or magnetic coupling. The chipsor interposers 670 may be coupled to the conductive patterns 12 usingelectroplated material, as described herein. The conductive patterns 12function as antennas when coupled to the chips or interposers 670. Eachof the combinations of a conductive pattern 12 and an chip or interposer670 functions as a passive, semipassive, or active RFID device 672, ableto transmit and/or receive signals. As an alternative, the chips orinterposers 670 may be attached prior to the transfer to the carrier 660in step 658, rather than subsequent to the transfer.

A second (attachment) adhesive film 680, for transferring the RFIDdevices 672 off of the carrier 660, is deposited in step 684. The secondadhesive film 680 has different adhesive properties from those of thecarrier adhesive layer 664. For example, the second adhesive layer 680may have substantially constant (non-switchable) adhesive properties, ormay have adhesive properties that change in a different manner fromthose of the carrier adhesive layer 664. Put another way, the carrieradhesive 664 and the second adhesive film 680 may have different releaseproperties. The second adhesive film 680 may be a suitablepressure-sensitive adhesive, or may be a hot melt adhesive withdifferent properties from those of the carrier adhesive 664. As afurther alternative, the second adhesive film or layer 680 may includean adhesive that does not need to be heated to be activated.

The second adhesive layer 680 may be sprayed, printed, or otherwisesuitably deposited. The second adhesive 680 may be a patterned andregistered placement of adhesive, so as to place the adhesive on theconductive pattern (antenna) 12, while avoiding placement of adhesive onthe carrier adhesive layer 664. The second adhesive 680 may be appliedusing a suitable patterned printing process. Alternatively, the secondadhesive film 680 may be a substantially uniform layer.

In step 686 one of the RFID devices 672 is transferred to an object 688,such as a carton or a product to be tracked. The second adhesive film680 may be used to secure the RFID device 672 to the object 688. Asdiscussed above, the carrier adhesive 664 and the second adhesive 680are selected such that the RFID device 672 is preferentially transferredfrom the carrier 660 to the object 688. The RFID device 672 may besingulated (cut or otherwise physically separated other devices on theroll) before or after being affixed to the object 672.

It will be appreciated that the carrier 660 of the system 654advantageously may be reusable. As shown in FIG. 32, the carrier 660 maybe a belt that transfers conductive patterns 12 from the conductive filmor substrate 18 to a series of the objects 688.

Finally, in step 690, a sealing layer 692 may be placed over the placedRFID device 672. The sealing layer 692 may be a sprayed layer of asuitable material to form a non-sticky coating, such as a suitableUV-curable acrylic coating. Alternatively, the sealing layer 692 may bea suitable polymer or paper layer, that may include printed matter, suchas words, symbols, or graphics. The sealing layer 692 may protectfragile components of the RFID device 672, such as the conductivepattern antenna 12 and the chip or interposer 670. The sealing layer 692may be placed on the RFID device 672 by a suitable mechanism, such as byuse of a suitable adhesive, for example a hot melt adhesive. It will beappreciated that the sealing layer 692 may be omitted, if desired.

FIG. 33 shows an alternative system 696, which omits the carrier 660(FIG. 32) entirely. In the system 696, the chips or interposers 670 arecoupled to the conductive pattern antennas 12 to form the RFID devices672, while the conductive patterns 12 are still adhered to theconductive foil substrate 18. An adhesive 698 is then applied to theRFID devices 672. The adhesive 698 performs a function similar to thatof the second adhesive 680 (FIG. 32), although it will be appreciatedthat there is no concern in the system 696 with needing to overcome thecarrier adhesive 664 of the carrier 660 (FIG. 32). The adhesive 698 maybe a hot melt adhesive, to give one example of a suitable class ofadhesives.

The RFID devices 672 are directly transferred from the conductivesubstrate foil 18 to objects such as the object 688. The adhesive 698permanently attaches the RFID device 672 to the object 688. The system696 reduces the number of steps required in forming and attaching theRFID devices 672 to the objects 688. In addition, the RFID devices 672are of minimal size and thickness, since the RFID devices 672 may eachconsist only of the conductive pattern antenna 12, and the chip orinterposer 670 coupled to the conductive pattern antenna 12.

Referring now to FIG. 34, a conductive foil or substrate 18 has apatterned low surface energy material mask 720 on parts of its surface.An exposed surface portion 724 corresponds to a desired shape and sizefor the conductive patterns 12 (FIG. 1) to be grown on the conductivefoil or substrate 18.

The low surface energy material of the mask 720 is a material that has alow peel strength value with regard to the adhesive 84 (FIG. 11) used topeel the conductive pattern 12 from the conductive foil or substrate 18.Such a low surface energy material may be broadly defined as a materialthat has less than the peel strength value, with regard to the adhesive84, as does the conductive pattern 12. It will be appreciated that thegreater the difference in peel strength value, the better the transferof the conductive pattern 12 in preference to the low surface energymaterial mask 720.

The low surface energy material of the mask 720 may include a lowsurface energy additive, such as silicone, that migrates preferentiallyto the exposed surface of the mask 720. Examples of suitable materialsinclude silicone-containing inks, such as Daw Ink 01AV26UV002, andsilicone-containing epoxies, such as Wearlon Super F-4 epoxy-siliconeand Wearlon 4545-76 epoxy-silicone. In 90-degree peel strength tests fora particular adhesive the above materials were found to have respectivepeel strengths of 0.097 lbs/in, 0.0108 lbs/in, and 0.044 lbs/in. Thiscontrasted with peel strengths of 0.639-1.05 lbs/in for UV-acrylic andTEFLON-containing surface coating materials. The peel strength of platedcopper on stainless steel (5 microns on a 200 grit finish) was found tobe 0.174 lbs/in.

FIG. 35 shows a vacuum roller 740 used to transfer conductive patterns12 from the conductive substrate or foil 18 to a destination, such as aweb of RFID devices 742. The vacuum roller 740 includes a series ofvacuum pores 744 that may be substantially evenly spaced about acircumference of a roller surface 748. The vacuum roller 740 providessuction at the vacuum pores 744, allowing lifting of the conductivepatterns 12 from the conductive substrate or foil 18. Rotation of thevacuum roller 740 moves the conductive patterns 12 to the RFID deviceweb 742, where the conductive patterns 12 are deposited. The device web742 may have an adhesive 750 on its surface to adhesively adhere theconductive patterns 12 and pull the conductive patterns 12 away from thevacuum roller 740. The roller surface 748 may be coated with a lowsurface energy material to discourage adhesive coupling between thevacuum roller 740 and the device web 742. Suitable coatings includesilicone and fluorocarbons, for instance. The vacuum roller 740 may moveat a substantially constant rotation rate, or alternatively may move ata variable rate. The vacuum roller 740 may be used to change the pitchof the conductive patterns 12 from the pitch on the conductive substrateor foil 18 to the pitch on the device web 742. It will be appreciatedthat alternatively that multiple vacuum rollers may be used to transferthe conductive patterns 12. Further details regarding use of rollers totransfer small devices may be found in U.S. Pat. No. 6,951,596, and inU.S. patent application Ser. Nos. 10/947,010, filed Sep. 22, 2004, and11/148,676, filed Jun. 9, 2005, the descriptions and figures of whichare herein incorporated by reference.

FIGS. 36-39 illustrate steps in the process of fabricating a multi-levelRFID device 760. FIG. 36 shows a conductive pattern 12 coupled to a chipor interposer 764 on a substrate 766. The conductive pattern 12 and thechip or interposer 764 together constitute a first circuit 770. Theconductive pattern 12 may be made according to the plating methodsdisclosed herein. The conductive pattern 12 may be transferred andcoupled to the substrate 766 by any of the methods disclosed herein, forexample being adhesively coupled to the substrate 766. It will beappreciated that the coupling to the substrate 766 may either betemporary or permanent. The chip or interposer 764 may be coupled to theconductive pattern 12 either before or after the transfer of theconductive pattern 12 to the substrate 766. As one example, the chip orinterposer 764 may be coupled by plated material joining the chip orinterposer 764 to the conductive pattern 12.

FIG. 37 shows a dielectric material layer 774 placed on top of most ofthe conductive pattern 12. The dielectric material layer 774 leavesopenings 776 for connection to the conductive pattern 12 or the chip orinterposer 764. The dielectric material layer 770 may be a printedlayer, and may be a layer of any of a wide variety of suitabledielectric materials, such as a UV-cured material. The dielectric layer770 may be sprayed on.

FIGS. 38 and 39 illustrate coupling of a second circuit 780 to the firstcircuit 770. The second circuit 780 may include a second conductivepattern 784 and a second chip or interposer (not shown). Alternatively,either the second conductive pattern 784 or the second chip orinterposer may be omitted from the second circuit 780. The secondcircuit 780 may be formed according to the plating and other methodsdescribed herein, and may be transferred to and adhesively adhered tothe dielectric material layer 774. The second circuit 780 may beelectrically coupled to the first circuit 770 through the openings 776in the dielectric layer 774. The electrical coupling between thecircuits 770 and 780 may be made by any of a variety of suitablemethods, such as by use of conductive pastes or by ultrasonic welding.

As shown in FIG. 38, the second circuit 780 may be registered to thefirst circuit 770 such that the second conductive pattern overlies thefirst conductive pattern 12. Alternatively, as shown in FIG. 40, thesecond circuit 780 may be registered relative to the first circuit 770such that the conductive patterns 12 and 784 are staggered relative toone another.

FIG. 38 also shows an additional component 782, such as a battery, thatis coupled to circuits 770 and 780. The additional component is oneexample of components that could be operatively coupled at or betweenlevels of the multiple circuits 770 and 780.

It will be appreciated that additional levels may be built up in thedevice 760, adding additional components and additional layers ofcircuitry, with layers of dielectric material between. The additionalcircuits and additional components may be offset or staggered so as tominimize the overall thickness of the multilayer device. The multilayerdevice 760 advantageously allows circuitry that could not be placed on aconventional circuit board (even a two-sided circuit board). Inaddition, the multilayer device 760 advantageously may be thinner andmore flexible than a conventional circuit board.

FIG. 40 shows an alternate arrangement system 800 for plating to formthe conductive patterns 12 on the conductive substrate or foil 18. Thesystem includes a U-bend cell 804 with a U-bend 806 in the conductivefoil 18. A pair of rollers 808 and 810 may be used to move theconductive substrate 18 along, and facilitate maintaining the U-shapebend portion 806 of the conductive foil or substrate 18. An electrolyte814 is on the inside of the U-bend cell 804. Side plates 816 and 818form sides of the U-bend cell 804. Seals 820 provide sealing between theside plates 816 and 818, and edges of the U-bend portion 806 of theconductive foil 18. The seals 820 are seals capable of maintaining theelectrolyte 814 within the U-bend cell 804 as the conductive foil 18moves along the U-bend cell 804, along the bottom edges of the sideplates 816 and 818. The seals 820 may be any of a variety of suitableseals, such as sliding seals or rotating seals.

The U-bend cell 804 has an electrode cover 824, functioning as an anodeand covering the top of the enclosure of the U-bend cell 804. A voltagesource 828 hooked up to the electrode cover and a back or bottom surface830 of the conductive foil 18 causes plating in exposed sections 834 ofa front or top surface 836 of the U-bend portion 806 of the conductivefoil or substrate 18. This plating forms the conductive patterns 12.

The use of the U-bend cell 804 advantageously limits plating to only thefront or top surface 836, without any need to coat the back or bottomsurface 830 of the conductive foil 18 with a dielectric material. Thisconcentrates the plating where it is useful, while maintaining easyaccess to electrical connection along the back or bottom surface 830 ofthe conductive foil 18. In addition, the U-bend cell 804 advantageouslyallows electrical connection to the foil 18 essentially within theelectrolyte bath, at locations along the conductive foil 18 wherein theconductive patterns 12 are being plated. This allows plating to beperformed more efficiently along the conductive foil 18, compared tosystems with connections removed from the plating bath. Placingelectrical connections to the foil away from the plating bathdisadvantageously results in voltage gradients along the foil thatreduce the voltages available for performing actual plating. Suchvoltage gradients along the foil are avoided by making electricalconnections to the foil 18 in the same part of the foil that is beingplated.

It will be appreciated that many variations are possible for the U-bendcell 804. The electrolyte 814 may be a colloidal electrolyte instead ofa liquid electrolyte. The colloidal electrolyte may be a porous gelelectrolyte or a foam electrolyte, for example. The use of a colloidalelectrolyte may make sealing of the cell 804 easier. Also, the cell 804may have a different shape, for instance confining the electrolyte to athin layer between the anode 824 and the conductive foil 18. That is,the electrode cover 824 may have a shape that is similar to that of theU-bend portion 804 of the conductive foil 18.

Referring now to FIG. 41, a conductive substrate or foil 860 has anarrangement that produces a continuous conductive pattern that is latercut, slit, or otherwise separated into individual antennas. Theconductive substrate or foil 860 has a series of unconnected maskelements 862 that are used to prevent plating where central holes of theresulting antennas would be. The mask elements 862 may be convexelements, such as the rectangles illustrated in FIG. 41. Alternatively,the mask elements 862 may have a wide variety of other shapes and/orconfigurations. The mask elements 862 may be made of dielectricmaterial, such as the mask materials described above. As will bedescribed further below, the continuous exposed surface 864 of theconductive substrate or foil 860 allows formation of the continuousconductive pattern, which may be continuously formed and removed from abelt or drum having the conductive substrate or foil 860 at its surface.

FIG. 42 shows an alternative conductive substrate or foil 870 thatincludes a treated preferential plating area 874 that is preferentiallyplated relative to an untreated area 872. The treated area 874 may be acontinuous area, and may be similar in configuration to the exposedsurface 864 of the conductive substrate or foil 860 (FIG. 41).

The treated area 874 may be treated in any of a variety of ways toimprove its ability to be plated. For example, the surface of thetreated area 874 may be roughened, such as by treating it with anabrasive, such as sandpaper. As an alternative, a granular conductiveseed layer may be printed in a pattern on the conductive foil orsubstrate 870 to produce the treated area 874 with improved platingproperties. As another alternative, suitable chemical etching orsandblasting may be used to produce the treated area 874.

FIGS. 43-45 show various systems for utilizing the conductive foils 860and 870 to produce a continuous conductive pattern 880. The system 884shown in FIG. 43 has the substrate or foil 860 or 880 as the surface ofan endless belt 886 located in a plating bath 888. The continuousconductive pattern 880 is continuously formed as the belt 886 is movedwithin an electrolyte 890 in the plating bath 888. At a location in thebath 888 the continuous conductive pattern 880 is separated from thebelt 886. The continuous conductive pattern 880 is pulled out of thebath 888 by a pair of rollers 892. Further steps may be taken to joinchips or interposers to the continuous conductive pattern 880, tosingulate individual antennas from the conductive pattern 880, and toproduce RFID devices from the continuous conductive pattern 880.

FIG. 44 shows an alternative system 894, with the conductive foil orsubstrate 860 or 870 on the surface of a drum 896, rather than on thebelt 886 shown in FIG. 43. The drum 896 is located in a bath 888containing an electrolyte 890 for plating the continuous conductivepattern 880 on the surface of the drum 896. The continuous conductivepattern 880 produced on the drum 896 may be pulled off the drum 896 andsubsequently collected in a manner similar to that shown in FIG. 43 anddescribed above.

FIG. 45 shows another alternative system 900, in which a continuousconductive pattern 880 is transferred from a belt 902 to a substrate904. The belt 902 has the conductive foil 860 or 870 on its surface. Thebelt 902 may be similar to the belt 886 (FIG. 43), and may operate in amanner similar to the belt 886. The conductive pattern 880 is separatedfrom the belt 902 onto the substrate 904 outside the electrolyte bath888. The separation may be an adhesive separation, as describedelsewhere herein. The separation onto the substrate 902 may beadvantageous when the conductive pattern 880 is fragile, or when theconductive pattern 880 needs to be attached to a substrate for anotherreason. Also, it will be appreciated that the conductive pattern 880that is attached to the substrate 902 may include certain noncontinuousconductive elements, if desired.

FIGS. 46 and 47 illustrates formation of an alternate embodimentconductive substrate or foil 958 which is selectively masked by forminga patterned surface oxide layer 960 on a part of its surface where theconductive pattern 12 (FIG. 1) is not to be formed. First a patternedremovable mask material 962 is deposited on the conductive substrate orfoil 958 in a pattern corresponding in size and shape to that of thedesired conductive pattern 12. An example of a suitable mask material isan elastomer material sold under the trademark VITON, available fromDuPont. Then the remaining exposed surface of the conductive substrateor foil 958 is oxidized to form the patterned surface oxide layer 960.The patterned surface oxide layer 960 may be formed by anodizing theexposed surface of the conductive substrate or foil 958 in a suitableanodizing bath. The removable positive mask 962 is then removed to leavethe conductive substrate or foil 958 shown in FIG. 48. The conductivesubstrate or foil 958 has a patterned exposed surface 964 correspondingin shape and size to the desired conductive pattern 12.

Titanium, aluminum, and niobium are examples of suitable metals for usein the conductive substrate or foil, although it will be appreciatedthat other suitable metals which form impervious insulating oxides uponanodization may be used instead. It also will be appreciated thatsimilar methods may be used for forming other sorts of dielectricmetallic compound masks.

FIGS. 48 and 49 illustrate part of a system 970 that involves formationof conductive patterns 972 on both sides (major surfaces) 974 and 976 ofa conductive substrate 978. The conductive substrate 978 may be a plate,belt, roller, or the like, with both of its major surfaces 974 and 976treated in any of the ways discussed above to allow formation ofconductive patterns by electroplating. The electroplating may beaccomplished by immersing the conductive substrate 978 in a platingbath, while applying a suitable current to the conductive substrate 978.

The conductive patterns 972 that form on both of the major surfaces 974and 976 may be removed from the conductive substrate 978 by any of themethods described herein, such as by use of a suitable adhesive. Theconductive patterns 972 may be coupled to label or tag substrates, or toobjects, as described elsewhere.

The system 970 advantageously increases output of the conductivepatterns 972 from the plating process. By plating on both sides (majorsurfaces) 974 and 976 of the conductive substrate 978, the output rateof conductive patterns may be effectively doubled.

Although the invention has been shown and described with respect to acertain embodiment or embodiments, it is obvious that equivalentalterations and modifications will occur to others skilled in the artupon the reading and understanding of this specification and the annexeddrawings. In particular regard to the various functions performed by theabove described elements (components, assemblies, devices, compositions,etc.), the terms (including a reference to a “means”) used to describesuch elements are intended to correspond, unless otherwise indicated, toany element which performs the specified function of the describedelement (i.e., that is functionally equivalent), even though notstructurally equivalent to the disclosed structure which performs thefunction in the herein illustrated exemplary embodiment or embodimentsof the invention. In addition, while a particular feature of theinvention may have been described above with respect to only one or moreof several illustrated embodiments, such feature may be combined withone or more other features of the other embodiments, as may be desiredand advantageous for any given or particular application.

1. A method of making an RFID device, the method comprising: printinggraphics on a front surface of a dielectric substrate; forming aconductive pattern on a conductive substrate; and after the printing,adhesively transferring the conductive pattern to a back surface of thedielectric substrate.
 2. The method of claim 1, wherein the adhesivelytransferring includes adhering the conductive pattern to an adhesivelayer on the back surface of the dielectric substrate.
 3. The method ofclaim 2, further comprising, after the adhesively transferring, coveringthe adhesive layer with a release layer.
 4. The method of claim 1,further comprising operatively coupling a chip to the conductivepattern, wherein the conductive pattern functions as an antenna whencoupled to the chip.
 5. The method of claim 4, wherein the chip is partof an interposer that also includes conductive leads attached tocontacts of the chip.
 6. The method of claim 4, wherein the chip iscoupled to the conductive pattern before the adhesively transferring. 7.The method of claim 4, wherein the chip is coupled to the conductivepattern after the adhesively transferring.
 8. The method of claim 1,wherein the method is part of a roll-to-roll process for making a rollof RFID devices.
 9. The method of claim 1, wherein the forming includeselectroplating to deposit the conductive pattern on the conductivesubstrate.
 10. An RFID device comprising: a dielectric layer; aconductive pattern antenna; a chip operatively coupled to the antenna;and an adhesive on the substrate; wherein the adhesive both attaches theantenna to the dielectric layer, and is configured for attaching theRFID device to an object that is not part of the RFID device.
 11. TheRFID device of claim 10, further comprising a release layer covering theadhesive.
 12. The RFID device of claim 10, wherein the adhesive is apressure sensitive adhesive.
 13. The RFID device of claim 10, whereinthe dielectric layer is a printable layer.
 14. The RFID device of claim13, wherein printed matter is printed on the dielectric layer on anopposite side from the adhesive.
 15. The RFID device of claim 10, aspart of a roll of RFID devices.
 16. A method of making a conductivepattern, the method comprising: plating the conductive pattern atop aconductive substrate that is partly covered with a mask made of a lowsurface energy material; and separating the conductive pattern from theconductive substrate.
 17. The method of claim 16, wherein the lowsurface energy material includes silicone, or fluorocarbon.
 18. Themethod of claim 16, wherein the low surface energy material includes alow surface energy additive that migrates preferentially to an exposedsurface of the mask.
 19. The method of claim 18, wherein the low surfaceenergy additive includes silicone.
 20. A method of forming an RFIDdevice, the method comprising: forming a first conductive pattern;coupling a chip to the first conductive pattern; positioning adielectric layer over the first conductive pattern; placing a secondconductive pattern on the dielectric layer; and coupling the secondconductive pattern to at least one of the first conductive pattern andthe chip.
 21. The method of claim 20, wherein the forming the firstconductive pattern includes electroplating the first conductive pattern.22. The method of claim 20, further comprising adhesively attaching thefirst conductive pattern to the dielectric substrate.
 23. The method ofclaim 22, wherein the forming the first conductive pattern includeselectroplating the first conductive pattern on a conductive substrate orfoil; and wherein the adhesively attaching includes adhesively peelingthe first conductive pattern from the conductive substrate or foil. 24.The method of claim 20, wherein the positioning the dielectric layerincludes positioning a dielectric layer with openings therein; andwherein the coupling occurs through the openings in the dielectriclayer.
 25. The method of claim 24, wherein the positioning thedielectric layer includes spraying the dielectric layer.
 26. The methodof claim 20, wherein the placing includes placing the second conductivelayer on a side of the dielectric layer opposite the first conductivelayer.
 27. The method of claim 20, wherein the conductive patternsoperate as an antenna to facilitate radio frequency communication withthe chip.
 28. A method of making conductive patterns, the methodcomprising: plating on a conductive substrate to form a plurality ofconductive patterns in a continuous sheet of conductive material;separating the continuous conductive material sheet from the conductivesubstrate; and singulating the conductive patterns.
 29. The method ofclaim 28, wherein the conductive substrate is part of a roller.
 30. Themethod of claim 28, wherein the conductive substrate is part of a belt.31. The method of claim 28, wherein the separating includes separatingfrom a location within a plating bath where the plating is performed.32. The method of claim 28, wherein the separating includes separatingby pulling along the conductive material sheet.
 33. The method of claim32, further comprising winding the conductive material sheet.
 34. Themethod of claim 28, further comprising treating treated areas of theconductive substrate or foil to alter plating properties.
 35. The methodof claim 34, wherein the treating includes roughening the treated areas.36. The method of claim 34, wherein the treating includes depositing agranular conductive seed layer on the treated areas.
 37. The method ofclaim 28, wherein the plating and the separating are performed as acontinuous process.
 38. The method of claim 28, further comprisingoperatively coupling chips to the conductive patterns to form RFIDdevices.
 39. A method of making conductive patterns, the methodcomprising: preparing opposite major surfaces of a conductive substratefor patterned electroplating; and simultaneously electroplatingconductive patterns onto both major surfaces of the conductivesubstrate.
 40. The method of claim 39, wherein the conductive substrateis a belt.
 41. The method of claim 39, wherein the conductive substrateis a plate.